The white coating on your tongue suggests oral thrush (a common, easily treatable fungal infection), while the recurrent ulcers may be aphthous ulcers or linked to vitamin deficiencies. For the white coating, an antifungal like Nystatin oral suspension or Clotrimazole lozenges is typically used. For ulcer pain relief and healing, you can apply a topical Lidocaine gel or Triamcinolone dental paste. Taking a daily B-complex vitamin supplement can also prevent future ulcers. Please practice good oral hygiene, rinse with warm salt water, and consult a doctor or dentist for a proper evaluation and prescription.